Vibratory-diaphragm controller



M. l. WILLIAMSON. Y VIBRATORY DIAPHRAGM CONTROLLER.

APPucATlou FILED MAY 13. 1919.

1,340,471, Patented May 1s, 1920.

MEDIUM MARSHALL I. WILLIAMSON, oF BALTIMORE, MARYLAND.

VIBRATORY-DIAPHRAGM CONTROLLER.

To all whom t may concern:

Be it known that I, MARSHALL I. WILLIAM- i soN, a citizen of the UnitedStates, residing of producing or reproducing sound or not,.

the object of the invention being to provide an improved means forcontrolling the vibrations of the diaphragme in such instruments.

A further object of theinvention is to provide a controlling means ofthe character set forth,.which is entirely independent of the elementsor forces which produce the vibrations of the diaphragms.

.A further object of the invention is to provide a controlling means ofthe character set forth, which is extremely simple in construction,economical to manufacture and highly eiiicient in operation.

With the foregoing and other objects in view, which will appear asthe'description proceeds, the invention consists in the novel featuresof construction and combination of parts which will be more fullydescribed hereinafter and particularly pointed out in the claim. A

Through experimental work and study I have discovered that while slightpressure, often in fact mere contact at' or about the center of avibrating diaphragm renders it for the time either nearly or completelyinactive, pressure near lthe edge of the diations by pressure on thediaphragm and so 5 5 produce regulating and maintaining such ressurethat an arbitrary control; over t e diaphragms vibrations may beaccomplished which in the case of sound producing instruments ormachines would result ina correspondin control over the volume of soundsSpecification of Letters Patent.

. Patented May 1S, 1920.

Application ledfMay 13, 1919. Serial No. $6,769.

In the drawings accompanying and forming a part of this specification. i

Figure l is a side view, Apartly in section, of a sound-receivinginstrument having my improved controller applied thereto, the instrumentbeing broken away at the rear thereof; n

Fig. 2 is a front end elevation thereof; and

Fig. 3'is a perspective view of a flexible pad forming one of theessential 'parts of the present invention.

The same characters of reference designate the same parts inthe severaldifferent figures of the drawings.

Referring to the drawings, 2 designates an ordinary telephone receiverhaving the usual coils 3 and magnetic. vibrators 4, and the usualdiaphragm 5 which vibrates in response to the fluctuating magnetic forceof the vibrators 4, the coils and vibrators being mounted in a housing 6of bell shape and on the outer end of which the diaphragm is seated andclamped thereto by means of a shoulder 7 carried by an annular member orat its outer end, and the space between the.

shoulder 7 and the shoulder 9 is threaded for cooperation with a capor-ear piece 10.

. An annular or washer-like pad 1l of flex-- 1ble material, such forinstance as cork,

felt, rubber, paper or other suitable material is mounted within thecircumferential shoulder i and is held centrally there-A within byengagement with the cap. 10. When not under pressure the pad contactsonly at its eXtreme outer circumferential edge with the diaphragm, itsinner side being inclined slightly, as shown, from its outer toward itsinner circumference, while its outer side is flat and is adapted to beengaged by the cap 10. By this construction it will be seen that byrotating the 4cap so as to press with greater force on the pad, thelatter will be forced into greater contact with the diaphra m from theouter cirmcumference thereo' toward the center and that in such mannerthe vibrations of the diaphragm may be controlled to any desired extent.For example, when it is desired to produce the maximum volume of soundthe cap 10 is rotated'so as to move it away from the pad thus lesseningthe latters contact and pressure upon the diadiaphragm until, if the padis wide i phragm, while when the minimum volume is desired it is rotatedso as to carry it toward the pad to the extreme of its inward movementthereby increasing the contact and pressure of the pad upon thediaphragm. I" other words, when the cap is moved outwardly as describedthe pad gradually assumes its normal shape thus gradually lessening itscontact with the diaphragm and increasing the vibrating area of thelatter until at the extreme outward movement of the cap, which isdetermined by the shoulder 9, the only contact of the pad with thediaphragm is 'at the extreme circumference of both, in which positionthe pad offers least resistance to the full activity of the diaphragmthus permitting the full volume of sound whereas when the cap movedinwardly, it gradually com4 presses the pad so that its contact with thediaphragm is gradita ly increased from its outer circumference inward J-thus gradually decreasing the vibrating area of the enough completeinaction of the diaphragm is accomplished and thus the complete absenceof sound.

The front of the annular member or ring 8 may be provided withdesignations, such as Loud, lt/iedium'" and Soft, and the outer face ofthe cap 1U with an arrow or similar mark for indicating` the properrelation between the cap and ring to produce the volume of sounddesired. The edge of the cap may be roughened7 as shown at l2, toprovide a grip to assist in turning the cap'. The inner face ofthe padis preferably scored as shown at 13 to prevent it adhering to thediaphragm after pressure has been withdrawn. The outer surface of thepad should be substantially stiffened so that it will remain always flatagainst the cap; in fact it may befound desirable to ralenti have theentire out-er surface of the pad securely fastened to the cap so as toprevent accidental or undesired shifting or change of position.'

lWhile I have described in detail the structure herein illustrated, itwill be understood that I donot thereby limit my invention to the.precise features of construction shown, as l am aware that manymechanical changes and modifications may be made therein withoutdeparting from the spirit and scope of the invention as set forth in theclaim hereto appended.

Having thus described my invention, what l claim is:

lin a telephone receiver, a housing, a vibratory diaphragm seating onthe outer end of the housing, an ear piece over the diaphragm, a ringcarried by said end of the housing and having an internal shoulderengage-able with the diaphragm adjacent to its periphery for clampingthe .saine to the housing end, said ring also having a second internalshoulder and being internally screw threaded between said shoulder andthe firstmentioned shoulder, the aforesaid ear piece haring a rearportion which is screwed into the aforesaid threaded portion of the ringand is adjustable between the shoulders, and an annular member betweenthe diaphragm and the ear piece and engageable with the former adjacentto its periphery, said ear piece being adjustable to force the aforesaidmember into contact with the diaphragm to a greater. or less extentradially thereof, thereby to vary the diameter of the vibratory portionof the diaphragm.

ln testimony whereof I aHiX my signature in the presence of twowitnesses.

MARSHALL l. VILLIAMSON.

Witnesses:

E. AVALTON BREWINGTON, HOWARD D. ADAMS.

